All though this doesn't look big here, it is actually just over 4 feet tall. It is isobarically loaded with two low frequency drivers that can handle 400 W rms and 800 W peak. The speaker has a dicast frame and 100 oz. magnet. This really gives you the feeling of bass and also sounds amazing. I was using a Yamaha amp to power it before my senior design amp. Both sound great with it. We got the plans for this box at Decware. They have many good build your own sub enclosures.